Editing Brugada syndrome (section)

== Signs and symptoms ==
Although many of those with Brugada syndrome do not have any symptoms, Brugada syndrome may cause fainting or sudden cardiac death due to serious abnormal heart rhythms, such as [[ventricular fibrillation]] or [[Ventricular tachycardia|polymorphic ventricular tachycardia]].<ref name=Pri2013 />  Blackouts may be caused by brief abnormal heart rhythms that revert to a normal rhythm spontaneously.  If a dangerous heart rhythm does not stop by itself and is left untreated, the person may have a fatal cardiac arrest. However, blackouts can occur in those with Brugada syndrome despite a normal heart rhythm, because of a sudden drop in blood pressure, known as [[Reflex syncope|vasovagal syncope]].<ref name="Pol2017" /><!-- quote = Syncope is common in BrS, occurring in 30% of patients [9]. Both arrhythmic and non-arrhythmic (reflex) syncope are observed with different prognostic implications. -->

The abnormal heart rhythms seen in Brugada syndrome often occur at rest, after a heavy meal, and even during sleep.<ref name=Sar2016 /> These situations are linked to periods when the [[vagus nerve]] is activated, referred to as periods of high [[vagal tone]]. Abnormal heart rhythms may also occur during [[fever]] and after excessive alcohol use. [[Sodium channel blocker|Sodium-channel-blocking]] medications, commonly used to treat cardiac arrhythmia, may also worsen the tendency to abnormal heart rhythms in patients with Brugada syndrome and should be avoided.<ref name="Postema_2009" /><ref name="Brugada Syndrome">{{cite web |url=https://rarediseases.org/rare-diseases/brugada-syndrome/#:~:text=Brugada%20syndrome%20is%20a%20rare%20inherited%20cardiovascular%20disorder,without%20treatment%2C%20may%20potentially%20result%20in%20sudden%20death. |title=Brugada Syndrome |publisher=NORD |date=2013 |website=National Organization for Rare Disorders |access-date=2021-11-28}}</ref>